There is a lack of an effective, reliable and manufacturable device to manage and cool fiber-optic cable, especially gain fiber, in high-power fiber-laser application to keep lengths of optical fiber neatly arranged and secured as well as to prevent detrimental heating effects, such as dopant diffusion in the gain fiber. Existing devices for optical fiber management and cooling tend to have input and output fiber located at significantly different physical planes (i.e., on opposite ends of a cylindrical fiber-management device), which creates undesired fiber bending. Further, existing optical-fiber-management devices tend to lack features that effectively secure the optical fiber to the management unit and existing devices also tend to require significant space, which is undesirable when a long optical fiber needs to be managed.
U.S. Pat. No. 6,424,784 issued to Grieg A. Olson on Jul. 23, 2002, titled “GRATING COIL PACKAGE FOR REDUCED FIBER STRAIN,” is incorporated herein by reference. Olson describes an apparatus and method for securing an optical fiber Bragg grating to a retaining element having a helical groove. In accordance with the method, an optical fiber Bragg grating is wrapped around the retaining element so that the optical fiber Bragg grating extends in and along the helical groove. An excess length of the optical fiber Bragg grating is provided in the helical groove to substantially alleviate tension exerted upon the optical fiber Bragg grating. The first and second ends of the fiber Bragg grating are affixed to the retaining element. The optical fiber apparatus and method described by Olson describes the optical fiber being looped around the outer surface of the apparatus and also requires that the optical fiber enter and exit the retaining element on different planes (i.e., the first end and second end of the fiber on the retaining element being in different parallel planes).
U.S. Pat. No. 7,400,812 issued to Martin Seifert on Jul. 15, 2008, titled “APPARATUS AND METHODS FOR ACCOMMODATING LOOPS OF OPTICAL FIBER,” is incorporated herein by reference. Seifert describes an optical apparatus for accommodating optical fiber, such as one or more loops of optical fiber. The optical apparatus can include a body comprising an inwardly facing surface adapted for receiving a plurality of loops of a length of optical fiber. The body can include at least a portion wherein the inwardly facing surface is continuous between two adjacent loops. Methods and apparatus are described for disposing the optical fiber with an optical apparatus for accommodating the optical fiber. The optical fiber apparatus described by Seifert described the optical fiber being looped around the inner surface of the apparatus and also requires that the optical fiber enter the apparatus and exit the apparatus on different planes (i.e., the first end and second end of the cylinder being in different parallel planes).
A peer-reviewed journal article published in the Proceeding of SPIE, Volume 7195, pp. 71951U-71951U-11 (Photonics West 2009), authored by Marc-André Lapointe, et al. and titled “THERMAL EFFECTS IN HIGH-POWER CW FIBER LASERS” is incorporated in its entirety herein by reference. Lapointe et al. describe that the thermal degradation of double clad optical fiber coatings is known to be the prime limiting factor for the operation of high-power continuous-wave (CW) fiber lasers. In this paper, the authors conducted a study of thermal effects in high power CW fiber lasers. A particular focus was put on heating at the splice points and in the doped fiber due to the quantum defect in 100-W class CW fiber lasers. A theoretical model, and experimental measurements taken with a high resolution IR camera on 125- to 400-micron-diameter (125-400-micrometer-diameter) fibers, were presented. Thermal-contact resistance between the fiber and its heat sink were considered in the conduction heat-transfer model and measured for different geometries. Proper designs for cooling apparatus were proposed and optimization of the active fiber was discussed. Some predictions for power scaling and temperature management of fiber lasers to kilowatt (kW) power level were also described.
There is a need for an improved apparatus and associated method for handling, managing and cooling optical-waveguide fiber optic cable.